//
//  NSData+Extensions.m
//  TelegramTest
//
//  Created by keepcoder on 05.10.13.
//  Copyright (c) 2013 keepcoder. All rights reserved.
//

#import "NSData+Extensions.h"
#import "zlib.h"
@implementation NSData (Extensions)
- (NSString *)hexadecimalString {
    /* Returns hexadecimal string of NSData. Empty string if data is empty.   */
    
    const unsigned char *dataBuffer = (const unsigned char *)[self bytes];
    
    if (!dataBuffer)
        return [NSString string];
    
    NSUInteger          dataLength  = [self length];
    NSMutableString     *hexString  = [NSMutableString stringWithCapacity:(dataLength * 2)];
    
    for (int i = 0; i < dataLength; ++i)
        [hexString appendString:[NSString stringWithFormat:@"%02lx", (unsigned long)dataBuffer[i]]];
    
    return [NSString stringWithString:hexString];
}

-(id)initWithEmptyBytes:(int)bytes {
    
    NSMutableData *data = [[NSMutableData alloc] init];
    
    for (int i = 0; i < bytes; i++) {
        int b = 0;
        [data appendBytes:&b length:1];
    }
    
    return data;
    
}


-(NSData *)gzipInflate;
{
    if ([self length] == 0) return self;
    
    unsigned full_length = (int) [self length];
    unsigned half_length = (int) [self length] / 2;
    
    NSMutableData *decompressed = [NSMutableData dataWithLength: full_length + half_length];
    BOOL done = NO;
    int status;
    
    z_stream strm;
    strm.next_in = (Bytef *)[self bytes];
    strm.avail_in = (int) [self length];
    strm.total_out = 0;
    strm.zalloc = Z_NULL;
    strm.zfree = Z_NULL;
    
    if (inflateInit2(&strm, (15+32)) != Z_OK) return nil;
    while (!done)
    {
        // Make sure we have enough room and reset the lengths.
        if (strm.total_out >= [decompressed length])
            [decompressed increaseLengthBy: half_length];
        strm.next_out = [decompressed mutableBytes] + strm.total_out;
        strm.avail_out = (int) ([decompressed length] - strm.total_out);
        
        // Inflate another chunk.
        status = inflate (&strm, Z_SYNC_FLUSH);
        if (status == Z_STREAM_END) done = YES;
        else if (status != Z_OK) break;
    }
    if (inflateEnd (&strm) != Z_OK) return nil;
    
    // Set real length.
    if (done)
    {
        [decompressed setLength: strm.total_out];
        return [NSData dataWithData: decompressed];
    }
    else return nil;
}

-(NSData *)dataWithData:(NSData *)data {
    NSMutableData *ndata = [self mutableCopy];
    [ndata appendData:data];
    return ndata;
}

- (NSData *)gzipDeflate;
{
    if ([self length] == 0) return self;
    
    z_stream strm;
    
    strm.zalloc = Z_NULL;
    strm.zfree = Z_NULL;
    strm.opaque = Z_NULL;
    strm.total_out = 0;
    strm.next_in=(Bytef *)[self bytes];
    strm.avail_in = (int) [self length];
    
    // Compresssion Levels:
    //   Z_NO_COMPRESSION
    //   Z_BEST_SPEED
    //   Z_BEST_COMPRESSION
    //   Z_DEFAULT_COMPRESSION
    
    if (deflateInit2(&strm, Z_DEFAULT_COMPRESSION, Z_DEFLATED, (15+16), 8, Z_DEFAULT_STRATEGY) != Z_OK) return nil;
    
    NSMutableData *compressed = [NSMutableData dataWithLength:16384];  // 16K chunks for expansion
    
    do {
        
        if (strm.total_out >= [compressed length])
            [compressed increaseLengthBy: 16384];
        
        strm.next_out = [compressed mutableBytes] + strm.total_out;
        strm.avail_out = (int) ( [compressed length] - strm.total_out);
        
        deflate(&strm, Z_FINISH);
        
    } while (strm.avail_out == 0);
    
    deflateEnd(&strm);
    
    [compressed setLength: strm.total_out];
    return [NSData dataWithData:compressed];
}

-(NSString *)binaryString {
    NSString *str = [self hexadecimalString];
    NSMutableString *binStr = [[NSMutableString alloc] init];
    
    for(NSUInteger i=0; i<[str length]; i++)
    {
        [binStr appendString:[self hexToBinary:[str characterAtIndex:i]]];
    }
    
    return binStr;
}

- (NSString *) hexToBinary:(unichar)myChar
{
    switch(myChar)
    {
        case '0': return @"0000";
        case '1': return @"0001";
        case '2': return @"0010";
        case '3': return @"0011";
        case '4': return @"0100";
        case '5': return @"0101";
        case '6': return @"0110";
        case '7': return @"0111";
        case '8': return @"1000";
        case '9': return @"1001";
        case 'a':
        case 'A': return @"1010";
        case 'b':
        case 'B': return @"1011";
        case 'c':
        case 'C': return @"1100";
        case 'd':
        case 'D': return @"1101";
        case 'e':
        case 'E': return @"1110";
        case 'f':
        case 'F': return @"1111";
    }
    return @"-1"; //means something went wrong, shouldn't reach here!
}


@end
